As technology progresses, wireless communications devices, such as smart phones, wireless capable computers, or the like, are becoming increasingly integrated, feature rich, and complex. Such wireless communications devices rely on semiconductor technologies, such as silicon based technologies, which are evolving toward smaller circuit geometries, lower power consumption, higher operating speeds, and increased complexity. Complementary metal oxide semiconductor (CMOS) technology is an example of a silicon based technology. Further, wireless communications devices may need to support multiple communications bands, multiple communications modes, multiple communications protocols, and the like. As such, wireless communications devices may need multiple RF switches to select between different RF circuits depending on which communications bands, modes, and protocols are in use. Such complex RF systems may place strict linearity, insertion loss, and isolation demands on the RF switches.
In general, RF switches having semiconductor-based switching elements may have a trade-off between insertion loss and isolation. RF switches that must handle high power levels may require low insertion losses. In order to achieve low insertion loss and high power handling capability, the size of circuit elements within an RF switch may be relatively large. However, such large circuit elements may be associated with relatively large capacitances, which may decrease isolation. Further, multiple large capacitances may have non-linearities, which may degrade linearity of the RF switch. Field effect transistors (FETs) may provide many of the characteristics needed to provide a good RF switch. However, when handling high power levels, single FETs may not have all of the necessary characteristics needed for an RF switch. As a result, stacked FETs may be needed for an RF switch. Thus, there is a need for stacked FETs that are compact and can be used to form an RF switch that improves the trade-off between insertion loss and isolation, has good linearity performance, operates over multiple frequency bands, or any combination thereof.